1. Field of the Invention
This invention relates generally to parabolic reflectors and more particularly to support structures, reflectors, tracking systems, and collectors therefore.
2. Description of the Prior Art
Many parabolic reflectors have been devised to focus solar rays on a point, at which a collector is placed, as typified by the D. E. Wood patents, numbered U.S. Pat. Nos. 4,171,876; 4,295,709; and 4,372,772, and the Osborn patent numbered U.S. Pat. No. 4,335,578. Where rays are focused on a point, rather than a line, greater tolerance is allowed for mis-alignment of reflectors. Where solar rays are focused on a line, i.e., on a linear collector, as typified by U.S. Pat. No. 4,407,129 issued to B. W. Johnson, focusing becomes more critical. Mirrored glass has been found to be the best reflector for solar rays, but large glass sections are prohibitively expensive. It is also highly desirable that the glass be curved to provide higher operating temperatures because of superior focus. Attempts have been made in the prior art to forcibly curve a plane sheet of glass, but such curvature is inadequate and distorted; extensive breakage may occur, and panes under such force are not individually focusable.